just because no matter what, i know that he is in an environment that he is surrounded by that makes him very safe. i'll get all teary. but, you know, i just -- he's my heart. he's my world. i just -- he's just my baby. >> mommy? we're going to decorate the cake for you. >> reporter: christina shared these intimate photos and home movies, and that bond between them shines through. she has built her world around max, literally. writing and recording at this studio at home to be with her son as much as she can. >> reporter: okay. >> that was for my special -- >> reporter: i'll never forget that. that was so great! the etta james picture. >> me and cher. photo booth style. >> reporter: i love it. this is where the magic happens? >> yep, this is where all the create consistityist. >> reporter: the studio to collaborate would her new friends from "the voice." she and adam worked together last year on tir number one hit, "moves like j and she recruited blake for one tune. and she brought celo on board, too. we caught them backstage as they got ready to debut their song. and then it was tim